A glitch allowed hackers to use "onmouseover" actions -- triggered when you hover your cursor over a link -- to send users to strange sites and send out gibberish-laden tweets. Users accessing Twitter through third-party clients were unaffected.

According to Twitter employees, it's safe to go back to Twitter.com now:

"Regarding the XSS attack, it should now be fully patched and is no longer exploitable. Thanks to those who reported it."